1. Field of the Invention
The present invention relates to a fire alarm system.
2. Description of the Related Art
In conventional fire alarm systems, fire monitoring or supervising terminals and control terminals for controlling smoke prevention/exhaustion equipment and other controlled equipment are connected to a reception unit such as a fire control and indicating equipment or a fire transmitter. The fire supervising and control terminals are realized with fire sensors or transmitters to which the fire sensors or devices to be controlled are connected.
The reception unit, for example, the fire control and indicating equipment receives fire information such as a fire signal or a physical quantity signal representing a fire phenomenon from a fire supervising terminal by, for example, polling the terminal. It is judged from the received fire information if a fire has broken out. A smoke prevention/exhaustion equipment associated with a district in which the fire has broken out is controlled based on the result of the judgment.
The foregoing fire alarm system judges from fire information, which the fire control and indicating equipment receives from a fire supervising terminal, if a fire has broken out. The fire supervising terminal is realized with a so-called analog fire sensor, a so-called on/off fire sensor, or a transmitter. The analog fire sensor transmits a physical quantity signal representing a fire phenomenon. The on/off fire sensor judges if the detected fire phenomenon stems from a fire, and transmits a fire signal in case of a fire. The transmitter has a plurality of on/off fire sensors connected thereto, and transmits a fire signal in response to a fire signal sent from any of the sensors.
The analog fire sensor includes a heat analog fire sensor, a smoke analog fire sensor, a flame analog fire sensor, and a gas analog fire sensor. The heat analog fire sensor transmits a physical quantity signal representing, for example, temperature. The smoke analog fire sensor transmits a physical signal indicating smoke. The flame analog fire sensor transmits a physical quantity signal indicating flame light (radiating light). The gas analog fire sensor transmits a physical quantity signal indicating gas. Moreover, the on/off fire sensor includes a heat fire sensor of a constant temperature type, differential type, or constant temperature differential type, a smoke fire sensor of a photoelectric type or ionization type, a flame fire sensor of an infrared type or ultraviolet type, and a gas-fire sensor. Moreover, the controlled equipment is mutually different in terms of a control time and control sequence.
For processing fire information sent from the analog fire sensor, the kind of fire information to be received varies depending on the type of the analog fire sensor. The reception unit such as the fire control and indicating equipment or transmitter to which the fire supervising terminals are connected must judge from the fire information if a fire has broken out. The same applies to judgment of a fire from a fire signal sent from the on/off fire sensor or transmitter. Moreover, the same applies to control of the controlled equipment.
In the conventional fire alarm systems, a reception unit such as a fire control and indicating equipment or a transmitter is provided with a so-called terminal mapping memory such as an EPROM. Identification number information that is type information of a plurality of fire supervising terminals or control terminals connected to the reception unit is stored in the memory. The identification number information stored in the memory is referenced in order to carry out fire supervising or a control sequence.
The memory is produced and incorporated in the reception unit at a factory before delivery of the reception unit. For example, after the fire alarm system is installed, the fire supervising terminals or control terminals may have to be changed or modified because of a change in the plan of a building or a change in the purpose of use. In this case, an EPROM in which the contents of the change or modification are described must be produced at a factory. Otherwise, an expert must bring a ROM writer into the installation site to rewrite the contents of an old ROM. It is thus time-consuming to renew a ROM. Moreover, a setting error may occur.